A new study, conducted by the researchers from the University of Wisconsin-Madison and Bar-Ilan University, suggests that different smiles may reduce or increase physical stress depending upon how they are perceived.

A team of scientists measured levels of cortisol in the saliva of 90 male undergraduate students. The researchers found that “dominance” smiles were associated with higher HPA axis activity, such as increases in heart rate and salivary cortisol.

The researchers write in their paper: “The findings provide further evidence for the view that smiles do not necessarily constitute positive nonverbal feedback, and that they may impact social interactions by affecting the physiological reaction of people who perceive them. In addition, cortisol appears to support the detection of social threat and coordinate biological activity needed to adequately respond to the threat.”

Japanese researchers Jun-ichiro Kawahara, associate professor at the Hokkaido University in Sapporo, and Takayuki Osugi, associate professor at Yamagata University in Yamagata, found that such popular non-verbal gesture as nodding can make you more popular.

For the study, the researchers asked 49 Japanese adults aged 18 and above to watch short clips of people nodding, shaking their heads, or staying still. Having analyzed the received data, the researchers found that nodding figures were 30% more likable and 40% more approachable than the motionless people or those shaking their heads.

Jun-ichiro Kawahara says: “Generalizing these results requires a degree of caution because computer-generated female faces were used to manipulate head motions in our experiments. Further study involving male figures, real faces, and observers from different cultural backgrounds, is needed to apply these findings to real-world situations.”

Your cravings for salty or sweet foods may be a sign of a lack of certain nutrients in your body, according to Jessica Crandall, a registered dietitian in Denver, Colorado.

Also, a study, published in the journal Physiology and Behavior, connected salt cravings to mineral levels in the body, as well as another study found that the highest amount salt cravings in women were linked to a deficiency in their calcium and magnesium levels.

Sweet cravings can be associated with sugar levels in your blood, but it also can be a habit, explains Crandall, for example, you get used to eating sweets after your lunch or dinner.

The nutritionist advises: “If you can keep a balance in your routine and find healthy modifications, then I think that’s an improvement.”

A new imaging genetics study, led by the Professor Elvira Brattico from Aarhus University and conducted in two Italian hospitals in cooperation with the University of Helsinki (Finland), has found the first evidence that the influence of music and noise on affective behaviour and brain psychology are associated with genetically determined dopamine functionality.

The study discovered that a functional variation in dopamine D2 receptor gene modulates the influence of music as opposed to noise on mood states and emotion-related prefrontal and striatal brain activity. Results of the study showed mood improvement after listening to music in subjects with GG genotype and mood deterioration after listening to noise in subjects with GT genotype.

The director of the study Professor Elvira Brattico says: “This study represents the first use of the imaging genetics approach in the field of music and sounds in general. We are really excited about our results because they suggest that even a non-pharmacological intervention such as music, might regulate mood and emotional responses at both the behavioural and neuronal level.”

In a recent study, published in the journal Nature Communications, scientists identified brain activity patterns that can predict a person’s confidence state and discovered that brain activity can be manipulated to increase self-confidence.

The team of researchers tested imaging technique “decoded neurofeedback” on 17 participants when they performed a simple exercise. They identified a specific brain activity that was connected to low and high confidence. The authors of the study believe that their findings can help us approach uncovering new ways to raise self-esteem and other important mental states.

All participants took part in training sessions. They received a small monetary reward when scientists noted states of high confidence. With the help of these training sessions, the scientists found that they were able to manage self-confidence in participants.